That piece also notes that the SNF viewership declines in late September/early October of 2017 (around those comments from Trump, which would be expected to produce the most significant effect if he was in fact altering the ratings) largely mirrored what happened in those months in 2016. And it adds that the 2017 drops in Trump-favoring markets were similar to the drops in Clinton-favoring markets during that time, further subtracting from the idea that Trump supporters tuned out the NFL en masse in a larger way than the rest of the population. The whole piece is worth a read for discussion of these various data points and how they got them, but here are the key takeaways:

There was some evidence of a Trump effect. But it was, at best, weak.

What really stood out was that people stuck with football if there was a “football reason” to watch. The data show that quality football and home team loyalty drove the TV audience far more than political tribalism.

…Places Trump won big — by 10 points or more — saw NFL TV ratings dip less than a single percentage point. That’s the same decrease as experienced in markets where neither candidate won by double digits.

Places Clinton won big also saw a tiny decline. It’s worth noting some pretty good football teams were in Clinton country, including three of four teams in last year’s conference championship games.

That overall decline graphic for Trump-favoring markets, Clinton-favoring markets and toss-up markets can be seen here:

It’s notable that that particular data excludes markets with their own team playing, and it shows a slight drop for Trump-favoring markets that just about corresponds to the one for toss-up markets. The Clinton-favoring markets held more steady, but that may be more about their teams being good. As the authors note earlier in the piece, a good local team tends to produce more interest in SNF games not involving that team, which makes sense; if your team’s good, you’re maybe more interested in seeing upcoming opponents and/or potential playoff rivals.

And on that note, it’s significant that many of the Trump-favoring markets that did see declines saw struggling local teams, so those ratings losses could be more about that than anything the president said. So all in all, this is far from proof of any Trump effect. And if there is one, it seems pretty small compared to other factors affecting the ratings.

Of course, this all needs to be taken with some caveats. This is just Sunday Night Football, not NFL ratings overall; it’s a good data set to look at considering that the Sunday night game is heavily marketed and that there’s only one game on at that time, but it’s not necessarily completely representative of all NFL ratings. Moreover, many of the comparisons are to 2016, and 2016 also saw significant ratings declines and Trump taking credit for some of that (that was more about political coverage around his presidential campaign, but he also took some shots at Colin Kaepernick and other protesting players at that time), so those who insist that it’s Trump behind ratings downturns might be able to argue that he was already having an effect then. But overall, the data seems to support the idea of Trump’s NFL criticisms being just one factor in ratings declines, and not a particularly large one.